I have two Sonos five set up as a stereo pair. Both are wall mounted and have not been moved a single time. Not moved or touched. Today I was listening to these days by Connor price when I heard a very obvious crackling sound coming from my left Sonos five at -0:45 till -0:43. everything else plays flawlessly, just that one part that dose not work. I have tried many things like unplugging it and re plugging it. But every time It happened. It is only the left one. It dose not happen when I set it to right on the eq or I turn down the bass from 5 to 0. it is only the left one and only when bass is turned up. I have no idea what it is. Btw both Sonos five are not the same version. They were bought a year apart. The left one dose not have a hexagon pattern / bee hive pattern in the mesh when shining light thorough it. The right one does. The left one is the older one but has never caused any problems. I have no idea what is cousins this problem. Thank you for reading this. Have a nice day.